The impact of grazing on mountain vegetation and the arbuscular mycorrhizal symbiont

In 2000 an enclosure experiment was established at one lowland ( 70 m a.s.l ) and one alpine (600 m a.s.l.) site in the Faroe Islands. After five years of enclosure, significant increases were seen in vegetation biomass at both altitudes as both the cover and vegetation height increased. Five species changed their abundance significantly. Only minor changes of species loss and gain were seen. Palatable grasses increased their abundance in enclosed plots, both at the lowland and the alpine site.
Roots from Agrostis capillaris were examined for arbuscular mycorrhizal (AM) colonisation, and the colonisation found to be greater at grazed plots. The plant species that had a significantly negative response to grazing were typically classified as normally mycorrhizal, while species that proliferated in grazed plots
were either classified as rarely mycorrhizal or as less palatable